Method and apparatus for strand crimping



Nov. 26, 1963 R. K. STANLEY METHOD AND APPARATUS FOR STRAND CRIMPING 2 Sheets-Sheet 1 Filed Feb. 2, 1959 z N f MW w T Nm 2 W3 m N T 5 m A m H W W 0 v m M Nov. 26, 1963 R. K. STANLEY METHOD AND APPARATUS FOR STRAND CRIMPING 2 sheets-sheet 2 Filed Feb. 2, 1959 W Y m M NH t 0 W5 T N r [K A m 6 6 M 2 1 J 8 I I W W l 7 a m 8 u I an 3 W H 1 a 1 m r w 5 v n a w 7M 1 l I a 7 6 8 MJW Mm m WPlIJ u f 9 u 7 I m m m. WW M an %W% 6 V 7 m 9 United States Patent 3,111,740 METHOD AND APPARATUS FUR STRAND CREMPING Robert K. Stanley, Plymouth Meeting, Pat, assignor to Techniservice Corporation, Philadelphia, Pa, a corporation of Pennsylvania Filed Feb. 2, 1959, Ser. No. 790,553 Claims. (Cl. 281) This invention relates to sniffer-crimping of textile strands, concerning particularly certain heating and cooling of the strands being stuifer-crimped.

Well known methods, primarily mechanical, of modifying the regularity of surface or rectilinearity of configuration of textile strands include gear-crimping, twistcrimping and stuffer-crimping. Preheating of the strand to be crimped is an accepted procedure in stutter-crimping, as well as in the other mentioned crimping methods. The strand to be crimped is forced by and between a pair of counter-rotating nip rolls into a confined region from which its escape is impeded, by suitable back-pressure means, sufiiciently to cause the strand entering the region to bend back and forth upon coming into forcible contact with the accumulation of strand already present therein.

It is also conventional in the stutter-crimping art to heat the chamber or other mechanical elements that provide the confining region, presumably in order to release the stresses induced in the strand by the mentioned bending, or at least to maintain the strand in heated condition until just before it leaves the region. The cooling of the strand subsequent to the heat treatment in the confining chamber is known also. Unfortunately, at least in part because of uneven or undue heating, the resulting strand often exhibits dyeing irregularity, evident as barre or similar difficulty, in fabrics composed of such dyed strands.

A primary object of the present invention is improved stutfer-crimping of textile strands having thermoplastic components. An object is improved heat exchange with, and temperature control of, a thermoplastic strand being stutter-crimped. A particular object is provision of stuffer-crimped textile strands of uniform dyeability. Other objects of the present invention, together with means and methods for attaining the various objects, will be apparent from the following description and the accompanying diagrams.

FIG. 1 is a block diagram illustrative of the present in vention; FIG. 2 is a schematic representation of practice of the invention in somewhat more detail than in FIG. 1; FIG. 3 is a front elevation, partly broken away, of a stuft'er-crimper and associated apparatus useful in practicing the invention; FIG. 4 is a plan of the same apparatus taken at 4-4 of FIG. 3; and FIG. 5 is a sectional plan taken at 55 of FIG. 3. FIG. 6 is a longitudinal section through a feed roll and associated elements of the same apparatus; FIG. 7 is a transverse section through a feed roll taken at 77 of FIG. 6; FIG. 8 is a circuit diagram of electrical components of the apparatus.

In general, the objects of the present invention are accomplished, in the treatment of a textile strand having a thermoplastic component, by heating the strand to soften the thermoplastic component, forcing the heated strand intoand through a region from which exit of the strand is impeded sufficiently to impart a crimped configuration thereto, and cooling the strand as soon as it assumes the crimped configuration. The invention contemplates accomplishment of this in apparatus comprising means for forwarding a strand through a heating zone and into a cooling zone contiguous with the heating zone, means for heating the strand being forwarded through the heating zone, means for cooling the strand throughout the coolheating zone.

ing zone, and a stuifer-crirnper having a stuffing chamber with its entrance juxtaposed to the boundary between the heating and cooling zones to receive the strand from the This invention also comprehends other features of stuifer-crirnping apparatus, as pointed out specifically below.

FIG. 1 represents in block form two contiguous Zones, a heating zone and a cooling zone, traversed in succession by a strand path with indication of performance of a stu'ifer-crimping step at the boundary between the two zones. Apparatus for practicing this process is represented diagrammatically in FIG. 2.

Strand it) is withdrawn from bobbin or similar package 11 through pigtail or similar guide 13 by forwarding rolls 14, 14 between which it passes. After the forwarding rolls, which themselves may be heated, the strand passes over heating block 5 to stutter rolls l6, 16 at hidden entrance to stuiiing chamber 17. The chamber is surrounded by cooling jacket 1%, and exit of the strand from the chamber is impeded by a back-pressure element (45, shown in FIGS. 3, 4, and 5). From the chamber the crimped strand (denoted as 16* to distinguish it from uncrimped portion 16) passes over idler roll 26 and is wound onto bobbin or cone 12 by contacting winding roll 22. It is to be understood that the stufiing chamber (enclosed in its jacket) extends in close-fitting manner well into the bight of the adjacent rolls and close to their nip. Details of such apparatus appear in the succeeding views.

FIG. 3 shows in front elevation (partly cut away) a stuffer-crimper useful according to the present invention. Besides rolls 16, 16' and jacket 19 about chamber 17, already shown schematically in FIG. 2, additional elements are shown in some detail in this View. Base 1 carries upstanding supports 26, 26' for the rolls and infeed guide 23, which conforms closely to the bight of those rolls, immediately underneath them. Bore 24 (shown in broken lines) of the guide is aligned with the nip of the rolls, and an arrow indicates the direction of passage of the strand to be crimped. Aligned with the nip and extending into the bight of the rolls from the rear is back-pressure gear 45. Depending front flange 29 of housing 19 is largely cut away in this view, along with part of the housing or jacket itself and the stuffing chamber, to reveal various interior elements of the apparatus. A corresponding flange (29, shown in FIG. 5) at the rear is slotted to receive the back-pressure gear but is hidden in this view.

The back-pressure gear is carried on shaft 47 mounted in upstanding supports 46, 46' (only one being visible in FIG. 3) carried on the base. The other end of the gear shaft carries pulley 27, about which passes belt 30. This belt loops over coupling 28, which attaches to one end of extension spring 42 and is secured non-rotatively by means of rivet 41. The other end of the extension spring is retained against the base by eye-bolt 43 secured by nut 44.

The base also supports motor 49, which has drive pulley 32 at-fixed to motor shaft 31. Belt 33 passes about the drive pulley and about a driven pulley (36, hidden in this view) mounted on shaft 21' of roll 16'. Rolls 16, 16 are retained on their respective axle shafts 21, 21 by hex nuts 34, 34 visible at the front. The rear wall of the stuffing chamber is slotted to receive the backpressure gear. Somewhat more than halfway up bore 25 of the chamber, leaf 55 is visible against the inside wall. The chamber emerges from the surrounding jacket at the top, where the front wall portion of the chamber is recessed below the level of the other wall portions. Bail St} pivoted at the sides of the chamber extends to the front and rests on the top of the recessed front wall portion, just visible above the top of the jacket. The lower part of the jacket is cut away to reveal the interior,

3,1 3 including deflecting fins $1 and helical circulating fins 52. The jacket is supplied with inlet and outlet tubes 57 and 58 at the bottom and top, respectively, for cooling fiuid, and is shown from a different viewpoint in FIG. 4-.

FlG. 4 is a plan view of the smiling chamber, the cooling jacket, and the inlet and outlet tubes for the jacket. Also shown are bail 59 on top of the recessed part of the chamber wall, leaf 55 against the rear wall, and back-pressure gear 4-5 extending into the chamber bore to the front of the leaf. The elements below the bottom of the inlet of the stufling chamber appear in plan in the next view. Air supply pipe as also appears.

FIG. 5 shows the apparatus of FTG. 3 in sectional plan, beginning at a level just above roll in at the left, progressing rightward past back-pressure gear 45', downward to the level of the roll axes, to the right side through the axis of roll 16, and then upward above and on to the right of pulley 27 and its associated elements. Thus, the left-hand roll and its axle and associated elements appear in full, while the right-hand roll and its axle and associated elements appear largely in section. The following description is limited to the right-hand roll and associated elements, the corresponding elements on the left side being the same and indicated by primed reference characters corresponding to the unprimed reference characters applied to the like right-hand elements.

FIG. 5 shows axle shaft 21, which carries roll 16, to be hollow except at the front end, longitudinal bore 191 so formed being closed at the rear by plug 81. This axle is mounted rotatably in front and rear ball-bearing assemblies $5 and 86, respectively, supported in respective front and rear walls 88 and 37 extending upward from base 1. Reference numerals for some of the elements mentioned appear in FIG. 6, which presents roll 16 and associated elements in greater detail.

Roll 16 has a central flange defining front and rear annular channels 91 and 92, respectively, designed to receive annular heatin elements (93 and 94, not shown in this View); the channels are closed by respective rings 95 and 96. The longitudinal bore of the axle communicates with the channels of the roll by way of oblique bores 167 and 169 through the axle and apertures ill and 1% through the flange of the roll. Rotating shield 37, with fins 3S, rests against the front edge of boss 1% on the axle and is held slightly away from the rear wall of the roll by intervening spacer 110. The rear edge of this boss adjoins the front ball-bearing assembly, grease shield llll is located on the axle shaft immediately to the rear of that assembly and ahead of the exposed electrical components. At the far end of the axle, just ahead of the rear ball-bearing assembly, is driven gear 3112 held by key 114-, and the axle surface intervening between the front and rear ball-bearing assemblies is covered by layer 113 of electrical insulation.

Recessed at intervals part way into the peripheral surface of the insulated layer are slip rings 115, 116, 117, and 118, each of which is underlain by apertures in the insulating layer and by adjoining apertures through the axle itself, of which only 125, 127, and 128 (for rings 115, 117, and H8, respectively) appear in this view. FIG. 5 also shows the brush assemblies for the slip rings, each ring having a pair of brushes in contact with it: pair 135 for ring 115, 136 for ring 116, 137 for ring 117, and 138 for ring 113. The brushes in each pair of such assemblies are connected to one another and to external leads (here omitted for clarity), as shown schematically in PEG. 8. Being supported by U-shaped bracket 152, whose upstanding arms are visible here, they are stationary.

FIGS. 6 and 7 show right-hand roll 16 and its axle shaft 21, together with the elements mounted thereon, in longitudinal and transverse sections, respectively. Corresponding views of left-hand roll 16' and its associated elements would be similar, of course. From this somewhat enlarged view, it is apparent that the roll is keyed i to the axle by key Thcrmistor T185, only the jacket of which is visible, is recessed in the flange of the roll just underneath the peripheral surface; it is connected through slip rings 116 and 118 by leads through apertures res and 133 extending through the flange of the roll and the axle, respectively, and apertures 126 and 128 extending obliquely through the axle. Apcrtures 197 and for one of the leads to the heating element appear also, but apertures M39 and 127 (previously shown) do not appear, being contained in the portion of the axle sectioned away. Heating elements 93 and 94 consist of annular metal housings 193 and 194, respectively, each filled with asbestos or similar insulation 15 5, having respective internal heating coils 197 and 198.

FIG. 8 shows the connections for the various electrical elements or" the above apparatus. In this circuit diagram, thermistor 185 is connected via slip rings 116 and 118 to ohmmeter M by way of brush pairs 136 and 138. Heating coils 13 7 and 198 are connected in parallel to one another and in series with an external power source (indicated schematically to be A.-C.) through slip rings 115 and H7 and the associated pairs of brushes and 137.

Operation of the apparatus is readily understood. The illustrated motor drives the belt affixed to the pulley on the left-hand roll axle. Rotation of that axle ensues, as does counter-rotation of the axle of the right-hand roll, inasmuch as the two axles are geared directly to one another. The relative sizes of the gears and of the rolls themselves (all shown equal here) are selected so that the peripheral surfaces of the respective rolls turn at identical linear speeds.

Each roll is heated by the internal electrical resistance elements connected by the internal and external leads and intervening slip rings to the source of electrical potential. The temperature of the rolls may be controlled by varying the current through the heating elements in any suitable manner in response to the temperature indication received by means of the thermistor. The desired temperature depends primarily upon the composition, denier, and finish or other surface characteristics of the filamentary strand to be processed and upon the processing rate and the roll pressure.

Uncrimped strand it is fed through the bore of the infeed guide and injected into the nip of the counterrotating rolls, which stuff the strand into the entrance of the jacketed chamber. The strand is heated by contact with the rolls and crimped by the rapid columnar collapse of the strand accumulating below the back-pressure gear, which penetrates the chamber from the back. Upon sufficient accumulation of the strand to rotate the backpressure gear against the frictional retardation imparted to it by slippage of the attached pulley against the belt in contact with it, the strand accumulation proceeds upward into the chamber proper, which is cooled by circulation of cooling fluid inside the jacket. Water ordinarily is suitable as the cooling fluid and is injected through inlet tubes 57 near the base of the jacket and against deflecting fins 51, which assure circulation of the water to the chamber wall in the vicinity of the entrance. The water circulates about the chamber within the jacket in contact Wtih the helical circulating fins and emerges through the outlet tubes near the top of the jacket. The heated strand begins to cool immediately upon its entrance into the chamber and continues to do so as it passes upward in the chamber, finally approximating the temperature of the Water in the jacket.

trands so treated according to this invention are characterized by even crimp, high bulk, and freedom from dye-streaking. Other benefits will become apparent to those undertaking to practice the claimed invention in all its aspects.

The claimed invention:

1. In treatment of a strand having a thermoplastic component to impart a crimp thereto by stul'llng the strand into a confined crimping zone, the improvement comprising heating the strand to soften the thermoplastic component, and simultaneously forcing the strand so heated into a crimping zone, crimping the strand in the crimping zone while in heat-softened condition, and cooling the strand as soon as it assumes the crimped configuration.

2. Strand-treating process comprising forwarding a thermoplastic strand in continuous manner through a zone wherein the strand is heated to-a temperature on the order of the softening temperature of the strand composition and into a contiguous zone wherein the strand is cooled below the softening temperature of the strand composition, and crimping the strand so heated by stuffing it into a temporarily confining region having its entrance located at the boundary between the heating and cooling zones, the confing region being adapted to receive an accumulation of strand for cooling therein.

3. In the stutter-crimping of a thermoplastic textile strand whereby crimps are formed therein upon passage of the strand from the nip of a pair of nip rolls into a confining chamber having its entrance juxtaposed to the nip of the rolls, the improvement comprising supplying heat from the exterior to the strand until it passes from the roll nip to the chamber entrance, extracting heat from the strand as soon as it enters the chamber, and continuing to extract heat from the strand as it passes through the chamber.

4. A stutEer-crimper for thermoplastic strands, comprising a stuffing chamber, a pair of nip rolls adapted to stuff a strand into and through the chamber, a backpressure element adapted to impede exit of the strand from the chamber, means for heating the nip rolls, and means for cooling substantially the entire chamber including the portion thereof nearest the nip rolls.

5. Strand-crimping apparatus comprising means for forwarding a strand through a heating zone and into a cooling zone contiguous with the heating zone, means for heating the forwarding means and thereby heating the strand being forwarded thereby, a stuiiing chamber located substantially entirely in the cooling zone with its entrance juxtaposed to the boundary between the heating and cooling zones to receive the strand from the forwarding means and conduct it through the cooling zone, the forwarding means comprising a pair of nip rolls located in the heating zone and adapted to stuff the strand into the chamber located in the cooling zone, whereby the boundary between the heating and cooling zones is closely flanked by the nip of the rolls and the entrance of the chamber, and cooling means associated with the stufiing chamber in the cooling zone and adapted to cool substantially the entire chamber from the entrance to the vicinity of the outlet end thereof and thereby cool the strand therein.

References Cited in the tile of this patent UNITED STATES PATENTS 2,090,669 Dreyfus et al. Aug. 24, 1937 2,277,086 Dreyfus Mar. 24, 1942 2,394,165 Getaz Feb. 5, 1946 2,575,833 Pfau et al. Nov. 20, 1951 2,575,839 Rainard Nov. 20, 1951 2,733,122 I-Iarele et al. Ian. 31, 1956 2,734,228 Hay Feb. 14, 1956 2,734,252 Shattuclr Feb. 14, 1956 2,758,358 Shattuck Aug. 14, 1956 2,760,252 Shattuck Aug. 28, 1956 2,793,418 Pfau May 28, 1957 2,949,659 Heijnis et al. Aug. 23, 1960 2,960,730 Shattuck Nov. 22, 1960 

1. IN TREATMENT OF A STRAND HAVING A THERMOPLASTIC COMPONENT TO IMPART A CRIMP THERETO BY STUFFING THE STRAND INTO A CONFINED CRIMPING ZONE, THE IMPROVEMENT COMPRISING HEATING THE STRAND TO SOFTEN THE THERMOPLASTIC COMPONENT, AND SIMULTANEOUSLY FORCING THE STRAND SO HEATED INTO A CRIMPING ZONE, CRIMPING THE STRAND IN THE CRIMPING ZONE WHILE IN HEAT-SOFTENED CONDITION, AND COOLING THE STRAND AS SOON AS IT ASSUMES THE CRIMPED CONFIGURATION.
 3. IN THE STUFFER-CRIMPING OF A THERMOPLASTIC TEXTILE STRAND WHEREBY CRIMPS ARE FORMED THEREIN UPON PASSAGE OF THE STRAND FROM THE NIP OF A PAIR OF NIP ROLLS INTO A CONFINING CHAMBER HAVING ITS ENTRANCE JUXTAPOSED TO THE NIP OF THE ROLLS, THE IMPROVEMENT COMPRISING SUPPLYING HEAT FROM THE EXTERIOR TO THE STRAND UNTIL IT PASSES FROM THE ROLL NIP TO THE CHAMBER ENTRANCE, EXTRACTING HEAT FROM THE STRAND AS SOON AS IT ENTERS THE CHAMBER, AND CONTINUING TO EXTRACT HEAT FROM THE STRAND AS IT PASSES THROUGH THE CHAMBER. 